This proposal requests support for the 1st Protein Transport Across Cell Membranes Gordon Conference, to be held June 12-17, 2005 at Colby-Sawyer College in New London, New Hampshire. This new meeting will focus on the latest discoveries that enhance our understanding of the mechanisms by which proteins are transported across or integrated into membranes in eukaryotic cells, bacteria and organelles (e.g., mitochondria and peroxisomes). Since >25% of all proteins in all cells must cross at least one membrane to be properly localized, protein translocation is one of the most fundamental problems in biology. The conference will address a wide range of topics including 1) the selection of proteins for translocation and their targeting to translocation sites, 2) the structure, function and assembly of translocation complexes and insertases, 3) reverse or retro-translocation, 4) constraints on the folded state of translocation substrates, 5) the maintenance of permeability barriers, 6) lateral transfer of membrane proteins into lipid bilayers, 7) the role of lipids in protein translocation and membrane protein integration, 8) the role of energy in protein transport, 9) the regulation of protein translocation and 10) novel protein translocation mechanisms. One of the main goals of this conference is to promote interactions among scientists who use diverse biochemical, genetic, genomic and structural approaches to understand fundamental mechanisms of protein transport across membranes. This conference was established primarily to compensate for a striking dearth of formal opportunities for scientists who work on different but conceptually or mechanistically related aspects of protein translocation to meet and exchange ideas. The participants at the Protein Transport Across Cell Membranes Gordon Conference will include the leaders in the field, drawn from academia, government and industry, as well as more junior scientists, including many graduate students and postdoctoral fellows who represent the future in this area. A major use of the support sought in this application is to assist such junior scientists to participate in the meeting. The Gordon Conferences are organized to maximize opportunities for discussion and for the presentation of the latest findings in the field, with poster sessions occurring every afternoon and discussion periods after each formal session.